Date: Thu, 18 Sep 2014 15:49:24 +0200 (CEST)
From: "Mkrtchyan, Tigran" <tigran.mkrtchyan@desy.de>
To: Mark Kirkwood <mark.kirkwood@catalyst.net.nz>
Cc: pgsql-performance@postgresql.org
Message-ID: <500744138.44329.1411048164322.JavaMail.zimbra@desy.de>
In-Reply-To: <541AB149.70504@catalyst.net.nz>
References: <88549888.42916.1411034301200.JavaMail.zimbra@desy.de>
 <541AB149.70504@catalyst.net.nz>
Subject: Re: postgres 9.3 vs. 9.4
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----- Original Message -----
> From: "Mark Kirkwood" <mark.kirkwood@catalyst.net.nz>
> To: "Tigran Mkrtchyan" <tigran.mkrtchyan@desy.de>, pgsql-performance@postgresql.org
> Sent: Thursday, September 18, 2014 12:17:45 PM
> Subject: Re: [PERFORM] postgres 9.3 vs. 9.4
> 
> On 18/09/14 21:58, Mkrtchyan, Tigran wrote:
> >
> >
> > Hi Folk,
> >
> > I am trying to investigate some performance issues which we have with
> > postgres
> > (a different topic by itself) and tried postgres.9.4beta2, with a hope that
> > it
> > perform better.
> >
> > Turned out that 9.4 is 2x slower than 9.3.5 on the same hardware.
> >
> > Some technical details:
> >
> >    Host: rhel 6.5 2.6.32-431.23.3.el6.x86_64
> >    256 GB RAM, 40 cores, Intel(R) Xeon(R) CPU E5-2660 v2 @ 2.20GHz
> >    2x160GB  PCIe SSD DELL_P320h-MTFDGAL175SAH ( on one 9.3, on an other one
> >    9.4 )
> >
> > postgres tweaks:
> >
> >
> > default_statistics_target = 100
> > wal_writer_delay = 10s
> > vacuum_cost_delay = 50
> > synchronous_commit = off
> > maintenance_work_mem = 2GB
> > checkpoint_completion_target = 0.9
> > effective_cache_size = 94GB
> > work_mem = 402MB
> > wal_buffers = 16MB
> > checkpoint_segments = 64
> > shared_buffers = 8GB
> > max_connections = 100
> > random_page_cost = 1.5
> > # other goodies
> > log_line_prefix = '%m <%d %u %r> %%'
> > log_temp_files = 0
> > log_min_duration_statement = 5
> >
> > in both cases databases are fresh - no data.
> >
> > Here is a results with pgbench.
> >
> >
> > 9.3.5:
> >
> > # /usr/pgsql-9.3/bin/pgbench -r -j 1 -c 1 -T 60
> > starting vacuum...end.
> > transaction type: TPC-B (sort of)
> > scaling factor: 1
> > query mode: simple
> > number of clients: 1
> > number of threads: 1
> > duration: 60 s
> > number of transactions actually processed: 96361
> > tps = 1605.972262 (including connections establishing)
> > tps = 1606.064501 (excluding connections establishing)
> > statement latencies in milliseconds:
> > 	0.001391	\set nbranches 1 * :scale
> > 	0.000473	\set ntellers 10 * :scale
> > 	0.000430	\set naccounts 100000 * :scale
> > 	0.000533	\setrandom aid 1 :naccounts
> > 	0.000393	\setrandom bid 1 :nbranches
> > 	0.000468	\setrandom tid 1 :ntellers
> > 	0.000447	\setrandom delta -5000 5000
> > 	0.025161	BEGIN;
> > 	0.131317	UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE
> > 	aid = :aid;
> > 	0.100211	SELECT abalance FROM pgbench_accounts WHERE aid = :aid;
> > 	0.117406	UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid
> > 	= :tid;
> > 	0.114332	UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE
> > 	bid = :bid;
> > 	0.086660	INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES
> > 	(:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);
> > 	0.035940	END;
> >
> >
> > 9.4beta2:
> >
> > # /usr/pgsql-9.3/bin/pgbench -r -j 1 -c 1 -T 60
> > starting vacuum...end.
> > transaction type: TPC-B (sort of)
> > scaling factor: 1
> > query mode: simple
> > number of clients: 1
> > number of threads: 1
> > duration: 60 s
> > number of transactions actually processed: 34017
> > tps = 566.948384 (including connections establishing)
> > tps = 567.008666 (excluding connections establishing)
> > statement latencies in milliseconds:
> > 	0.001879	\set nbranches 1 * :scale
> > 	0.000526	\set ntellers 10 * :scale
> > 	0.000490	\set naccounts 100000 * :scale
> > 	0.000595	\setrandom aid 1 :naccounts
> > 	0.000421	\setrandom bid 1 :nbranches
> > 	0.000480	\setrandom tid 1 :ntellers
> > 	0.000484	\setrandom delta -5000 5000
> > 	0.055047	BEGIN;
> > 	0.172179	UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE
> > 	aid = :aid;
> > 	0.135392	SELECT abalance FROM pgbench_accounts WHERE aid = :aid;
> > 	0.157224	UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid
> > 	= :tid;
> > 	0.147969	UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE
> > 	bid = :bid;
> > 	0.123001	INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES
> > 	(:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);
> > 	0.957854	END;
> >
> > any ideas?
> >
> 
> Hi Tigran,
> 
> Some ideas:
> 
> 60s is too short for reliable results (default settings for checkpoints
> is 300s so 600s is the typical elapsed time to get reasonably repeatable
> numbers (to ensure you get about 1 checkpoint in your run). In addition
> I usually do
> 
> psql <<!
> CHECKPOINT;
> !
> 
> Plus
> 
> $ sleep 10
> 
> before each run so that I've got some confidence that we are starting
> from approximately the same state each time (and getting hopefully only
> *one* checkpoint per run)!


Sure, I can run a longer tests with longer breaks in between.


9.3.5

# /usr/pgsql-9.3/bin/pgbench -r -j 1 -c 1 -T 600
starting vacuum...end.
transaction type: TPC-B (sort of)
scaling factor: 1
query mode: simple
number of clients: 1
number of threads: 1
duration: 600 s
number of transactions actually processed: 1037297
tps = 1728.826406 (including connections establishing)
tps = 1728.836277 (excluding connections establishing)
statement latencies in milliseconds:
	0.001471	\set nbranches 1 * :scale
	0.000456	\set ntellers 10 * :scale
	0.000411	\set naccounts 100000 * :scale
	0.000524	\setrandom aid 1 :naccounts
	0.000364	\setrandom bid 1 :nbranches
	0.000437	\setrandom tid 1 :ntellers
	0.000424	\setrandom delta -5000 5000
	0.024217	BEGIN;
	0.118966	UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;
	0.092483	SELECT abalance FROM pgbench_accounts WHERE aid = :aid;
	0.108232	UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid = :tid;
	0.107978	UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE bid = :bid;
	0.080137	INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);
	0.034015	END;

9.4beta2

# /usr/pgsql-9.3/bin/pgbench -r -j 1 -c 1 -T 600
starting vacuum...end.
transaction type: TPC-B (sort of)
scaling factor: 1
query mode: simple
number of clients: 1
number of threads: 1
duration: 600 s
number of transactions actually processed: 373454
tps = 622.422377 (including connections establishing)
tps = 622.429494 (excluding connections establishing)
statement latencies in milliseconds:
	0.001252	\set nbranches 1 * :scale
	0.000417	\set ntellers 10 * :scale
	0.000384	\set naccounts 100000 * :scale
	0.000466	\setrandom aid 1 :naccounts
	0.000344	\setrandom bid 1 :nbranches
	0.000411	\setrandom tid 1 :ntellers
	0.000397	\setrandom delta -5000 5000
	0.047489	BEGIN;
	0.157164	UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;
	0.119992	SELECT abalance FROM pgbench_accounts WHERE aid = :aid;
	0.141147	UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid = :tid;
	0.132492	UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE bid = :bid;
	0.108917	INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);
	0.889112	END;


Tigran.


> 
> Cheers
> 
> Mark
> 


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